Automatic gun charger



2 Sheets-Sheet l B. STEVENS ETAL AUTOMATIC GUN CHARGER Jan. 12, 1960Filed Oct. 11, 1956 6%!76 J. Wasjez a. N Qt Jan. 12, 1960 B. STEVENSETAL 2,920,530

AUTOMATIC GUN CHARGER Filed Oct. 11, 1956 2 Sheets-Sheet 2 Yvd Q J! J 666 Jzveni'args 58 Barnard Jieue/u zyene J. Weasel BY Wm HFTOENEYSAUTOMATIC GUN CHARGER Bernard Stevens, Skokie, and Eugene S. Wassel, LaGrange, Ill., assignors to the United States of America as representedby the Secretary of the Air Force Application October 11, 1956,SerialNo. 615,440

6 Claims. (Cl. 89-1) This invention relates to a gun charger, and moreparticularly, to an automatic charging deviceof the pneumatic typeemployed for charging an automatic gun during gun fire when a failure totire occurs.

The main purpose of the present invention is to pro vide a new andimproved gun charging device of the type employing a simple andeffective electro-pneunratic system for charging an automatic gun duringgun fire when the gun fails to fire usually rendering the gun inactiveor even causing damage to the gun.

The gun charging device of the present inventionis further characterizedby its light weight and relatively small size, and by requiring only asmall amount of fluid pressure for its operation, which fluid pressuremay be supplied from the fluid pressure system of the aircraft.

It is further the purpose of the present invention to provide a guncharging device of this character which is of single action, i. e., thecharger piston or plunger may be returned to its initial forwardposition by the action of the gun operating slide rather than by fluidpressure acting on the opposite side of the charger piston as in the gunchargers of the prior art.

The gun charging device constructed in accordance with the presentinvention is further provided with a system consisting: of a fluidpressure motor or fluid pressure operated actuator and a valve assemblyfor controlling operation of the fluid pressure motor. The valveassembly is arranged to be moved to its open position by the action of asolenoid and to its closed position by the action of the charger pistonor plunger in the fluid pressure motor at the end of its rearwardstroke, after which the plunger is returned to its initial forwardposition in the fluid pressure motor by the action of the gun operatingslide. The solenoid may be actuated by manually closing the solenoidcircuit, or it may be actuated automatically by the action. of anautomatic control upon failure of the gun to fire when the firingcircuit of the gun is closed.

These and other features of the. present invention are described indetail below in connection with the accompanying drawings wherein likenumerals designate like parts, and in which:

Figure I is a side elevation, partly in section, of a gun chargingdevice embodying the present invention and mounted on the receiver of anautomatic gun;

Figure 2 is an end view, partly in section, of the device of Figure 1;

Figure 3 is a fragmentary view of the device of Figure 1 showing thevalve assembly in its forward position;

Figure 4 is a longitudinal section of the valve member employed in thedevice of Figure 1; and

Figure 5 is an end view of the valve member of Figure 4.

Referring now in detail to the drawings, the gun charging deviceillustrated in the drawings as an embodiment of the present invention isindicated generally by the reference numeral and, asshown, comprises afluid pressure motor or fluid pressure operated actuator 11 whichconsists of a cylinder assembly 12 and a valve assembly 14 2,920,530Patented Jan. 12, 1960 2. housed in the forward section. 16 of thecylinder assembly 12. The fluid pressure motor 11 is mounted on a gunreceiver 18 by a mounting bracket 20, provided on either side of thereceiver 18 for mounting the fluid pressure motor 11 either on the rightor left side of the gun receiver 18, as shown in Figure 1.

The mounting bracket 20 is formed with an opening 22 through which isinserted the fluid pressure motor 11. A groove 24 across the top of thecharger cylinder assembly 12 is arranged to. be aligned with a mating internally threaded hole 26 in the receiver mounting bracket 20, and a pin28 is screwed in tight. A locked nut 30 is tightened against bracket 20.The pin 28 properly positions the fluid pressure motor 11 in alongitudinal direction with respect to the gun receiver 18' and alsoproperly orients the fluid pressure motor 11 to clear the gun sliderail, not shown. in this manner, the fluid pressure motor 11 of thecharging device 10may have a free travel of a fraction of an inch beforecontacting a gun operating slide as indicated at 32. This free travelpermits the gun to counterrecoil a, fraction of an inch before strikingthe fluid pressure motor as hereinafter described.

The cylinder assembly 12 of the fluid pressure motor 11 consists of acylinder 34 and a hollow cylindrical piston or plunger 36 having a head38, and a skirt 40 arranged for reciproca-tory movement in the cylinder34. The hollow cylindrical piston 36 isalso formed with a cutawayportion 41 at the skirt 40 for avoiding interference with the sliderail, not shown, when extended rearwardly, and is further arranged to beslidably supported by a guide ring 42 and a transversely extending pin44 in the rear end of the cylinder 34. The pin 44 prevents the piston 36from rotating in the cylinder 34-. The piston head 38 is furtherprovided with a bore 46 through which extends a valve stem control rod48, which also extends through the skirt 44), as shown in Figure 1 Thecontrol rod 48 is provided with a head- 50 at the rearward end thereofslidably'engaging the inner wall of the piston skirt 40. A coil spring52 inserted over the control rod 48 and abutting the control rod head 50is acting as a buffer when an outer shoulder 54 of the control rod 48,which shoulder 54 is formed by the control rod head 50, is engaged by aninner shoulder 56 of the piston 36 just before the end of the rearwardstroke of the piston- 36. The piston head 38 isalso provided withsuitable packing rings 57- for forming a fluid tight joint with theinner wall of the cylinder 34 and with the outer wall of the valve stemcontrol rod 43.

Fluid pressure control for actuating the piston 36 is obtained by thevalve assembly 14 housed in the forward section 16 of the cylinderassembly 12, as described above, and provided with a valve stem member58 arranged in the valve housing section 16 for reciprocatory movement.The valve member 58 consists of a rear stem section 60 having a stud 62supporting a valve seat washer 64. and threadedly engaged by a forwardvalve stem section 66. A pin 67 prevents relative rotation of the valvesection 66 on the stud 62, as shown in Figure 4. The rear valve stemsection 60 is further formed with fluid passages 68, as shown in Figure4, and with a T -slot" 70 at the rearward end thereof, in which T-slot70 fits a T-shaped end 72 extending from the front end of the valvecontrol rod 48. The front valve stem section 66 is also provided with anouter shoulder 74, located substantially at the middle section of thevalve member 58,v and with a forward shoulder 76 against which abuts acoil spring 78 fitted over the valve section 66 and extending betweenthe shoulder 76 and a spacer collar 80. At its front end, the spring 78abuts against the front end' of the collar.80. The spacer collar 80 alsoretains in place a plurality of O seals 82 and. a spacer ring 84. Thespacer collar 80 is further held in place by a valve cap 86 threadedlyand a longitudinal bore 94 in fluid communication therewith.

' Extending through the longitudinal bore 94 in the valve cap 86 is anextension 96 of the valve member 58, which extension 96 has a T-shapedend 98 arranged to fit in a T-slot 100 in solenoid plunger 102 of asolenoid 104 threadedly secured in the forward end of the valve cap 86.A stop nut 106 is provided for adjusting the solenoid 104 in the valvecap 86 as seen in Figure 1. The solenoid 104 is also provided with asocket 107 at the forward end thereof for connection with an electricalcontrol system, not shown.

In operation, fluid under pressure enters the valve housing 16 throughan inlet 108 therein from a source, not shown, and exerts a force uponthe surface area of the shoulder 74 of the valve stem member 58. Inaddition, a force is exerted on the valve member 58 by the valve spring78 at the forward end thereof thereby holding the valve in its rearwardposition against its seat 64 and sealing the cylinder 34 against fluidpressure by preventing admission of fluid pressure through a port 110 influid communication with the cylinder 34. When the solenoid 104 isenergized, the valve member 58 and the valve stem rod 48 are pulledforward a fraction of an inch, opening the port 110 to the cylinder 34.Simultaneously, fluid pressure enters an annular space 112 at the rearof the valve housing 16, and through longitudinal passages 114, only oneof which is shown, enters the space between the front end of the valvemember 58 and the valve cap 86 and exerts a force on the surface area ofthe shoulder 76. Also, the fluid pressure exerts a force on the surfacearea of a curved rear valve shoulder 116. Thus, fluid pressure isapplied to both ends of the valve, but, because of the larger area ofthe curved shoulder 116 at the rear portion of the valve member 58, adifferential resulting force holds the valve member 58 against itsforward seat at 118, as shown in Figure 3, and thereby prevents escapeof fluid pressure through the forward exhaust ports 93 formed by thepassageways 92 in the valve cap 86. Fluid pressure entered in thecylinder '34 through the port 110 then acts upon the piston or plunger36 moving it rearwardly in contact with the gun operating slide 32. Whenthe piston 36 is within a fraction of an inch of the end of its stroke,it contacts the buflfer spring 52 on the valve stem rod 48 and pulls thevalve stem rod 48 and the valve member 58 by a force applied through thebulfer spring 52. This action moves the valve member 58 to its rearwardposition and the valve seat 64 prevents fluid pressure through the valveport 110 thereby sealing the cylinder 34 against fluid pressure. Thespring 52 must also be further compressed an additional fraction of aninch after the valve member 58 is in the closed position before thepiston 36 can contact the retaining bushing or guide ring 42 in the endof the cylinder 34. At the same time, air pressure exhausts through thebore 94 and the fluid passageways 92 in the valve cap 86, which are nowopen, and again the fluid pressure acts on the surface area of the valvemember shoulder 74 and holds the valve member 58 against its rearwardseat 64. The piston 36 in the meantime is returned to its forwardposition, as shown in Figure l, by the forward movement of the gunoperating slide 32. The fluid pressure in the cylinder during theforward movement of the piston is exhausted through the fluid passages68, annular space 112, longitudinal passageways 114, and through valvecap bore 94, fluid passageways 92 and exhaust ports 93 to atmosphere.

' The present invention has been described in detail above for purposesof illustration only and is not intended to 4 v be limited by thisdescription or otherwise except as defined in the appended claims.

We claim:

1. A charging device for an automatic gun comprising a fluid pressureoperated actuator arranged to engage and move a gun operating slide forcharging the gun, said actuator provided with a valve assembly having amember for controlling fluid pressure to said actuator, said valveassembly having a first fluid inlet passageway to deliver fluid underpressure therein and said valve member having an intermediate shoulderin communication with said first'inlet passageway and exposed to fluidpressure delivered into said first fluid inlet passageway normallyholding said valve member in a closed position thereby preventing fluidpressure to said actuator, valve opening means for moving said valvemember to .an open position, said valve assembly having a second aforward abutting shoulder of relatively large surface area and a rearcurved shoulder of relatively small surface area spaced therefrom inrespective opposed communication with fluid pressure delivered into saidsecond fluid inlet passageway and said interconnecting fluid passageswhile in the open position to effect a resultant force which tends toretain said valve member in the open position thereby admitting fluidunder pressure to said actuator to move said actuator to contact andmove the gun slide to a retracted position.

2. A charging device for an automatic gun as defined in claim 1, andelongated valve closing means attached to said valve'member at one endthereof and adapted to be engaged at a predetermined interval by saidactuator at the other end thereof to actuate said valve-closing meansfor'returning said valve member to the closed position at the end of thestroke of said actuator.

3. A charging device for an automatic gun comprising a fluid pressuremotor adapted to be mounted on a gun and arranged to contact and move agun operating slide to a retracted position for charging the gun, saidmotor having 'a valve housing defining a first inlet passageway, a portin communication with said fluid pressure motor, and an outlet, a valvemember in said valve housing for controlling fluid motor pressure tosaid motor, said valve member having a first outer abutment incommunication with said first inlet passageway and thereby exposed to,fluid motor pressure for normally retaining said valve member in itsseated position to close said port, biasing means tending to urge saidvalve member to its closed-port position, said valve housing having asecond fluid inletpassageway and intercommunicating longitudinallydisposed fluid passages in communication with said second fluid inletpassageway and said valve member having a second outer abutment spacedfrom said first-named abutment and a gradually diverging'shoulder spacedfrom said second abutment in respective communication with said secondfluid inlet passageway and said intercommunicating longitudinallypressure through said port to said motor for contacting and moving thegun slide to a retracted position.

4. A charging device for an automatic gun as defined in claim 3, andmeans in said fluid motor for moving said valve member in opposition tothe resultant force on said second abutment and said gradually divergingshoulder for closing said valve port and opening said valve outlet atthe end of the fluid motor stroke.

5. A charging device for an automatic gun comprising a cylinder adaptedto be mounted on a gun and provided with a plunger arranged to contactand move a gun operating slide to a retracted position for charging thegun, a valve housing defining a port in communication with saidcylinder, a valve member in said housing for controlling fluid pressureto said cylinder through said port, said valve member having a firstabrupt, peripheral projection exposed to fluid pressure for normallyholding said member against said port to seal said cylinder againstfluid pressure, said valve member having a second abrupt, peripheralprojection and a gradually sloping projection spaced longitudinally onopposite sides of said first projection and adapted to be exposed tofluid under pressure, said valve housing being provided with fluidpassageways between said projections on opposite sides of said firstprojection, and actuating means for moving said valve member inopposition to the fluid pressure exerted on said first projection ofsaid valve member for exposing said projections on opposite sides ofsaid first projection to fluid pressure the resultant force of whichtends to hold said valve member in a forward open position therebyadmitting fluid under pressure into said cylinder for actuating saidplunger to move the gun slide to a retracted position.

6. A charging device for an automatic gun as defined in claim 5 and inwhich said plunger is of hollow substantially cylindrical shape, andsaid valve member is provided with an extension extending through saidhollow plunger, said valve member extension having an outer shoulder,and said plunger having an inner shoulder arranged to engage said valvemember extension outer shoulder for moving said valve member inopposition to the resultant force of the fluid pressure exerted on saidprojections on opposite sides of said first projection against said portthereby sealing said cylinder against fluid pressure at the end of thestroke of said plunger, said plunger arranged to return to its initialposition in said cylinder by the forward movement of the gun operatingslide.

References Cited in the file of this patent UNITED STATES PATENTS2,384,834 Grant et al. Sept. 18, 1945 2,409,623 Grant Oct. 22, 19462,411,877 Heizer Dec. 3, 1946 2,423,446 Grant July 8, 1947 2,575,368Thomsen Nov. 20, 1951

